NSAPI Filters

In previous versions of the Web Server, the NSAPI API allowed multiple
SAFs to interact in request processing. For example, one SAF could be used
to authenticate the client after which a second SAF would generate the content.

In addition to the existing NSAPI interfaces, Sun Java System Web Server
introduces NSAPI filters that enable a function to intercept (and potentially
modify) the content presented to or generated by another function.